116 BRITISH ASSOCIATION TOE THE 



generator thereof, which he showed were strongly corroborative of the previous 

 results. He next examined the question of the size of the conducting wire ; and 

 he had the opportunity of testing the application of the law, as enunciated by 

 Prof. Thomson last year. The results, far from confirming the law, are strikingly 

 opposed to it. The fact of trebling the size of the conductor augmented the 

 amount of retardation to nearly double- that observed in the single wire. The 

 author, however, looked for the experimentum cruris in the limit to the rapidity 

 and distinctness of utterance attainablo ia the relative distances of 500 and 1,020 

 miles. 350 and 270 were the actual number of distinct signals recorded in equal 

 times through these two lengths respectively. These figures have no relation to 

 the squares of the distance. "Now, if the law of the squares be held to be good 

 in its application to submarine circuits, and if the deductions as to the necessary 

 size of the wire, bssed upon that law, can be proved to be valid also, we are driven 

 to the inevitable conclusion that submarine cables of certain length to be success- 

 ful must be constructed in accordance with these principles. And what does this 

 involve? In the case of the Transatlantic line, whose estimated length will be no 

 less than 2,500 miles, it would necessitate tha use, for a single conductor only, of 

 a cable so large and ponderous, as that probably no ship except Mr, Scott Russell's 

 leviathan could carry it, — so unwieldy in the manufacture, that its perfect insula- 

 tion would be a matter almost of practical impossibility, — and so expensive, from 

 the amount of materials employed, and the very laborious and critical nature of 

 the processes required in making and laying it out, that the thing would be 

 abandoned as being practically and commercially impossible. If, on the other 

 hand, the law of the squares be proved to be inapplicable to the transmission of 

 signals by submarine wires, whether with reference to the amount of retardation 

 observable in them, the rapidity of utterance to be attained, or the size of con- 

 ductor required for the purpose, then we may shortly expect to see a cable not 

 much exceeding one ton per mile, containing three, four or five conductors, 

 stretched from shore to shore, and uniting us to our Transatlantic brethren, at an 

 expense of less than one-fourth that of the large one above mentioned, able to 

 carry four or five times the number of messages, and therefore yielding about 

 twenty times as much return in proportion to the outlay. And what, I may be 

 asked, is the general conclusion to be drawn as the result of this investigation of 

 the law of the squares applied to submarine circuits? In all honesty, I am bound 

 to answer, that I believe nature knows no such application of that law ; and I can 

 only regard it as a fiction of the schools, a forced and violent adaptation of a 

 principle in Physics, good and true under other circumstances, but misapplied here." 

 In reply to this, Prof. W. Thomson writes to the Atheneum, that he believes 

 Mr. Whitehouse's results are reconcileable with his theory, because he is confident 

 that the theory is true, though he is not confident that he sees the true way of 

 reconcilement; and, in the mean time, he believes that a more "matter of fact" 

 proof must be afforded of the possibility of attaining sufficient capacity of com- 

 munication through a cable 1,000 miles long, than Mr. Whitehouse's experiments 

 supply. Mr. Whitehouse, in answer, says, that this "matter of fact" proof has 

 been given — in short — "we have recently telegraphed at a commercially satisfactory 

 speed through an unbroken subterranean circuit of 2,000 miles." Prof. Thomson, 

 (Atheneum, Nov. 1,) now enters into an elaborate discussion, in which he appears 

 to concede the question so far as the practical working of the telegraph is con- 

 cerned with the "law of squares :" he shews that in results calculated from the 



